G - Physics – 11 – B
Patent
G - Physics
11
B
352/32.21
G11B 7/08 (2006.01) G11B 7/085 (2006.01) G11B 7/09 (2006.01) G11B 11/00 (2006.01) H04N 5/83 (2006.01)
Patent
CA 1195424
ABSTRACT OF THE DISCLOSURE In an optical reproducing apparatus including an optical pickup device directing a light beam at a record medium surface and having at least one photodetector which produces a focus error signal in accordance with the state of focus of the light beam in respect to the record medium surface, and a focus control device responsive to a drive signal for controlling the focus of the light beam in respect to the record medium surface; there are provided a signal generator for producing a preliminary focusing signal which initially varies rapidly toward a first predetermined level of one polarity and then varies relatively slowly toward a second predetermined level of opposite polarity; a detecting device for detecting a zero crossover point of the focus error signal and producing an output signal which varies from a first level to a second level when the zero crossover point is detected; and switching circuitry for supplying the preliminary focusing signal to the focus control device as the drive signal for the latter when the output signal of the detecting device is at its first level and supplying the focus error signal to the focus control device as the drive signal for the latter when the output signal of the detecting device is at its second level. -1-
418765
Katsuyama Akira
Kimura Shuichi
Gowling Lafleur Henderson Llp
Sony Corporation
LandOfFree
Control circuitry for preliminary focusing of light on a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Control circuitry for preliminary focusing of light on a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Control circuitry for preliminary focusing of light on a... will most certainly appreciate the feedback.
Profile ID: LFCA-PAI-O-1271514